Swab type applicator



y 1969 v H. C. GUSTAFSON 3,443,562

' SWAB TYPE APPLICATOR Filed March a. 1967 Sheet- 0:2

IJINVENTOR.

l HARRY c. GUSTAF ON F167 v 5W d g ATTORNEY May 13, 19697 H. C. GUSTAFSON SWAB TYPE APPLICATOR Sheet Filed March 8, 1967 0 1 E 5 mwW/flw y M 1 m V 1% m m d W/ United States Patent 3,443,562 SWAB TYPE APPLICATOR Harry C. Gustafson, Milwaukee, Wis., assignor to Fuller Laboratories, Inc., Eden Prairie, Minn., a corporation of Minnesota Filed Mar. 8, 1967, Ser. No. 633,327 Int. Cl. A6lm 35/00 U.S. Cl. 128-269 10 Claims ABSTRACT OF THE DISCLOSURE A swab or medical type with swab fibres imbedded in the swab carrying sticks. They are imbedded by using a solvent for the plastic sticks. The swabs are moistened during contouring to improve the strength of the sticks.

My invention relates to swab type applicators, and more particularly to swab applicators and their method of construction.

It is manifest to anyone familiar with medical swabs, or applicators, that the fibrous material used to construct the swab portion creates a hazard when the strands become disengaged, or separated from the mass. Then too the problem of adherently attaching the fibers to a conventional stick requires an adherent agent, or binding agent which may create or cause irritations, or toxic conditions.

The major purpose of my invention is to provide a swab constructed in a manner to eliminate the need for an adhesive agent for attaching the fibrous material to the stick.

Still another purpose of my invention is to provide a swab or applicator of the character described that is nontoxic, thereby preventing irritating effects when used for medicinal purposes.

A further purpose of my invention is to provide a means, or method, that will enable the strands of the absorbent material constituting the swab to be absorbed by, and made a part of, the stick for positive engagement therebetween.

A related purpose is to create a swab making method which permits faster movements of a stick conveyor in a continuous movement swab making process than is possible with adhesives.

Other and further purposes of the invention will become more apparent as the description proceeds, when taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a view of the end of a completed and assembled swab, or applicator, showing the formed fibrous material, applied to a conventional stick, or stem;

FIGURE 2 is an end view of a stick treated to form a plastic surface;

FIGURE 3 is a similar view of the end of the stick with fibrous material (shown in cross-section), formed to a predetermined contour, applied to the stick;

FIGURE 4 is a cross-sectional view of the treated stick or tubular construction shown in FIGURE 2, and taken at the line 4-4 therein;

FIGURE 5 is a cross-sectional view of FIGURE 3, taken at line 5-5 therein;

FIGURE 6 illustrates the step of winding fibrous material around the stick;

FIGURE 7 is a fragmentary view in cross-section showing the step of conveying sticks over the upper portion or surface of a circular member for rotatably applying a plasticizing agent to the stick;

FIGURE 8 is a cross-section of the view shown in FIGURE 7, taken at the line 88 therein;

FIGURE 9 is a diagrammatic view of a machine for carrying out the method herein disclosed;

FIGURE 10 is a diagrammatic view of a stick and fibrous mass being smoothed between a forming channel and moistening band; and

FIGURE 11 is a side view of the facilities used in the machine of FIGURE 9 for feeding, tearing and forming the fibrous material on the sticks.

Similar characters of reference indicate corresponding parts throughout the several views, and referring now to the same, the character 10 shows a swab stick which may be any desired length and which may be solid, or tubular in cross-section, and formed to any shape or contour on its outer peripheral surface. Stick 10 is constructed of a nontoxic plastic material, such as high-impact Styrene. The stick is preferably tubular as shown.

Medical applicator sticks of this type may range in length from about two or three inches to eight inches and in some cases longer. The stick diameter is oftentimes on the order of 7 to /3 of an inch. Such stick dimensions are known to the art.

Stick 10 is adapted to carry a swab 11, which is constructed of long strand fibrous material, such as rayon, nylon, cotton or the like, and is formed on the end of the stick 10. Swab 11 is formed to any shape or contour.

The fibers are fixed to the stick by applying a free flowing highly volatile solvent-like material to the swab carrying portion of the stick and in such amounts as to cause the surface of that portion of the stick to become tacky without causing any material change in the cross-section or shape of that portion. The solvent used should be one which leaves no trace of toxicity in the finished swab. In practice, the amount applied may make the swab carrying portion of the stick appear as is seen in FIGURES 2 and 4. The surface is plasticized slightly by the material so that it may flow around the fibers which are applied to it, and thereafter solidify.

Preferably, a mixture of 98.2% by volume Shell toluene, and methylene chloride 1.8% or a Shell GL- solvent or the equivalent is applied to a portion of the surface of the styrene stick. This softens the surface shown at 12 in FIGURE 2 to a sticky consistency.

After the surface is made tacky, the ends of an elongated fiber mass are brought into contact with the surface and the fiber ends adhere to the surface. The stick is revolved, as indicated in FIGURE 6, until the fibers are wound spirally to form superimposed layers of fibers as in the swab of FIGURE 5.

The mixture is highly volatile and evaporates promptly permitting the styrene to solidify, thereby embedding the fibers of the rayon, or the like, constituting the swab 11.

The fibers must be applied to the stick quickly after it becomes tacky inasmuch as the solvent evaporates and the stick portion solidifies sufiiciently that it loses its tackiness (within approximately 15 to 20 seconds.

In this manner, the application of an adherent agent is entirely eliminated, and, inasmuch as the tacky surface is a part of the stick 10, the fibers become a part thereof.

The softener is applied and the fibers are wound under ordinary ranges of room temperature, pressure and humidity conditions.

Other materials, such as perchlorethylene, ethylene dichloride, methylene chloride, a material known in the trade as Comsolv #100, methyl ethyl ketone, acetone, and certain grades of lacquer thinners may be used as the solvent to make the stick surface tacky.

The fibrous material may be cotton, rayon, nylon, or fibrous paper which has been separated from a continuous strand of such material.

Although it is not a necessity to the practice of the invention, it is most convenient in the manufacturing process to use a solvent that not only leaves no trace of toxicity in the finished swab but also has relatively little toxicity in the liquid condition. This makes working conditions more pleasant and tends to minimize problems of traces of toxicity being present in packages for the swabs. The solvent selected should also be such that it does not react chemically with the fibrous material used.

The swab-making process may be carried out by conveying sticks along a conveyor, rotating the sticks during such movement, applying the softener at an initial stage of such movement, and winding the fibers and shaping the swab during such movement, as is disclosed in my copending application Ser. No. 203,189, filed June 18, 1962, now Patent No. 3,263,280 as shown herein in FIGURES 9, l and 11.

For example, the solvent shown as 14 in FIGURES 7 and 8 may be carried in a container 15. A circular disk 16 which is partially submerged in the liquid 14 is revolved in any practical manner in the direction shown by the arrows in FIGURE 7, conveying the liquid 14 upward at 17 to the sticks 10, rotated in the direction shown by the arrows and carried past the disk by a conveyor 13. Disk 16 is rotatably supported on shaft 18 which is journaled at 19 in bearings shown as being an integral part of container 15. As is disclosed in my aforesaid patent, conveyor chain 13 is endless and is supported on an idler drum 37 so that when the drive sprockets for the chain are actuated, the conveyor carries the sticks .11 past the transfer roller 16 where they are wetted with solvent and then carries them upwardly to the fiber feeding station wherein a feeding and tearing roller 78 tears a predetermined length of fibrous mass from an elongated strand supply and feeds it into engagement with the rotating stick as shown in FIGURES 6 and 11. The chain 13 may carry angle members 48, each of which receives a stick from a stick-feeding mechanism in the form of a conveyor chain 29, all as described in my aforesaid patent. After a stick has received its mass of fibers and has wound them spirally thereabout, the chain continues to move it to a moistening area as described in my aforesaid patent wherein a pliable band 76 receives moisture from a tap 77 so as to moisten the band and the fibrous mass. A contouring surface 75 underlies the band 76 so as to cooperatively shape the fibers therebetween during moistening and contouring thereof, all as described in my aforesaid patent. The sticks may be rotated conveniently by means of an overlying belt 51 which spins the sticks during their movement, all as described in the aforesaid patent. The completed swabs are then delivered to a tray 66.

The time interval between the application of the solvent and the time that the fibers are fed into contact with the sticks as represented in FIGURES 6 and 11 should be such that the stick end is tacky before the fibers first reach the stick end. This insures that the stick will adhere to the ends of the fibers and bring about proper winding thereof on the stick. In this regard, some solvents may require little more than a fraction of a second between the time of application of the solvent and the time that the stick is tacky, whereas other solvents may require several seconds or more between the time that the solvent wets the end of the stick and the time that the stick end becomes sufiiciently tacky to pick up the fibers. As examples of this, sticks .wetted with Shell G.L.l00 solvent are tacky within about one second after application of the solvent. Sticks wetted with acetone require several seconds or more after wetting before they are sufficiently tacky to pick up the fiber end portions for proper winding. The time interval represented by the length of the conveyor chain between the solvent applying roller 16 and the fiber feeding drum 78 in FIGURES 9 and 11 is sufficient for some solvents. This time interval may, of course, be increased by reducing the speed of movement of the conveyor chain and decreased by increasing the speed of movement of the conveyor chain .13. This time interval also may be increased in a machine of the type illustrated 4 in FIGURES 9 through 11 simply by spacing the transfer roller further from the fiber feeding drum. As a further alternative in increasing the time interval, the stick ends may be wetted with solvent by placing the transfer roller alongside the stick delivery chain 29 at point A in FIG- URE 9.

In other types of swab-making apparatus operated at relatively high speeds as, for example, in some indexing types of machines, an elongated chain may be provided to first wet the sticks and then deliver them to the indexing wheel of the machine in timed synchronized relation with the movement of the indexing wheel, thereby providing a sufiicient time interval between the time of wetting the stick ends and the time of application of the fibers so as to insure a tacky surface which will pick up the ends of the fibers which are to be wound about the sticks.

It is advantageous to use moistening facilities as disclosed in my aforesaid patent when using the process as herein described. The application of moisture appears to retard and minimize any deteriorating effect which the solvent has on the stick end portions. In this regard it has been observed that in some cases without using the addition of moisture during the contouring of the swab or swabs that some swabs may be structurally weak in the stick end portions and sufficiently weak that they may be distorted rather readily and in some other cases the end portions of the sticks may be broken off with bending pressure equivalent to that used when applying a medicant to the hand with a swab. The reason for this is not known. In any event, the addition of moisture to the fibers is advantageous in producing commercially acceptable swabs. While it is possible to moisten the fibers before they are wound on the stick, the fibers adhere to the stick more readily, at the time of initial application to the stick, when they are dry. Hence, it is preferable to moisten the fibers after they are fed to the stick and at least partially wound, as illustrated in FIGURES l0 and 11.

The fact that the liquid 14 produces a tacky surface for contact with the fibers of the material constituting the swab 11 eliminates the application of any foreign adhesive agent for the construction of the assembled swab, or applicator. Since the liquid evaporates quickly, the liquid does not affect the finished swab.

Greater speeds are possible when using the present invention rather than liquid adhesives in a continuous swabmaking process, apparently because contact alone between the sticks and solvent will produce the tacky surface, whereas with adhesives, the time of contact must be sufficiently slow as to allow adherence of the adhesive to the stick. When conveyor speeds are high, the sticks tend to slide over the adhesive without a sufficient amount of the adhesive adhering to the stick.

Other forms of plastic sticks and solvents may be used with the principles of the invention. For example, plastic sticks known in the trade as high temperature A.B.S. may be used with an M.E. ketone solvent. This plastic material may be heat-sterilized whereas the styrene plastic will not stand such heat and must be wet-sterilized.

This application is a continuation-in-part of my copending applications Ser. No. 349,235, filed Mar. 4, 1964, and Ser. No. 390,858, filed Aug. 20, 1964.

Whereas I have shown and described an operative form of the invention, it should be understood that this showing and description thereof should be taken in an illustrative or diagrammatic sense only. There are many modifications in and to the invention which will fall within the scope and spirit thereof and which will be apparent to those skilled in the art. The scope of the invention should be limited only by the scope of the hereinafter appended claims.

I claim:

1. The method of forming swab type applicators including the steps of applying a volatile, nontoxic, solvent to the end portion of a tubular applicator stick formed from a plastic material which will become tacky under application of said plasticizer, the amount of solvent applied being such as to temporarily plasticize only the outer surface of said end portion and without materially changing the shape of said end portion, and applying fibrous material to said end portion while the surface is in at least a tacky state, winding said fibers around said stick to form a swab and thereafter allowing said end portion to solidify, thereby fixing said fibers to said stick.

2. A swab made in accordance with the method set forth in claim 1.

3. The method of claim 1 characterized by and including the step of moistening the fibers after said fibers are applied to said stick.

4. The method of claim 1 wherein said fibers are applied to said stick after a time interval following application of said solvent suflicient to allow said stick end portion to become tacky.

5. The method of forming swab type applicators including the steps of applying a volatile, substantially nontoxic solvent-like plasticizer to substantially the entire periphery of the end portion of an applicator stick having an end portion of substantially uniform diameter and formed from a material which will become tacky under application of said plasticizer, the amount of solvent applied being such'as to temporarily plasticize only the surface of said end portion, and thereafter, following a time interval of sufficient duration to allow the end portion of said stick to become tacky, applying fibrous material to said end portion while the surface of said end portion is in at least a tacky state to there-by fix said material substantially uniformly about said periphery, winding said fibers around said stick to form a swab and thereafter allowing said end portion to solidify, thereby fixing said fibrous material to said stick, and moistening said fibers during the steps recited.

6. The method of claim 5 wherein said plasticizer is applied to said sticks by a transfer roller.

7. The method of claim 5 wherein said steps are performed as said stick is conveyed along a path in a swabmaking machine.

8. A swab type applicator including an elongated plastic stick and a body of fibrous material spirally wound about and overlying one end portion of said stick to form a swab thereon, the inner portions of said fibrous material being embedded in the surface material of the stick proper substantially uniformly and all the way around the circumference of the stick end portion, the stick having essentially the same cross-sectional shape and dimensions through said end portion and the remainder of the stick, said stick end portion being free from barb-like obstructions and adhesive material foreign to the stick.

References Cited UNITED STATES PATENTS 3,179,108 4/1965 Blooh et a1 l28-269 3,255,494 6/1966 Blooh et al. 19145.3 3,343,540 9/1967 Siegel l28-269 ADELE M. EAGER, Primary Examiner.

US. Cl. X.R. 

